Yahoo TV

The United States is relocating its Ukraine embassy operations from the capital Kyiv to the western city of Lviv, Secretary of State Antony Blinken said on Monday, citing a "dramatic acceleration in the buildup of Russian forces."

The move comes as U.S. officials warned that Moscow was continuing to amass more than 100,000 troops near Russia's border with Ukraine and in neighboring Belarus, and could launch an attack at any time.

State Department spokesman Ned Price said the move is based on Russia's threatening military posture.

"We are basing our assessment on what we are seeing on the ground with our own eyes, which is a continued and unprovoked Russian buildup on the border with Ukraine and no accompanying evidence of de-escalation."

Most embassy staff have already been ordered to depart Ukraine and U.S. citizens have been advised to leave the country by commercial means.

Pentagon spokesperson John Kirby on Monday warned that if Russia were to attack Ukraine, there would be casualties on both sides.

"Should they conduct another major military operation, real lives will be at risk. Ukrainian lives, to be sure, but also Russian lives. This will not be bloodless."

Moscow denies Western accusations that it is planning an invasion.

Russia suggested on Monday that it was ready to keep talking to the West to try to defuse the security crisis. Russian foreign minister Sergei Lavrov said diplomatic possibilities are "far from exhausted."